The present invention relates to a control device managing a plurality of nodes and to a node device cooperating with the control device.
In a system capable of recognizing poisoning data attached to uncorrectable data, when an existing node receives the poisoning data, a data packet containing the poisoning data is sent to an existing node situated at a posterior stage. Therefore, a fault detection rate is improved without detecting unnecessary uncorrectable errors. The uncorrectable data is defined as the data that can not be corrected. Further, the uncorrectable error is defined as the data error that can not be corrected. “Poisoning” connotes that when the node receives the uncorrectable data, respective bits of an ECC (Error Correcting Code) attached to a tailing part of the data are converted into a specified pattern (data). Namely, the poisoning comes under one category of the term “uncorrectable”.
Data processing can be executed at the existing node at the final stage by flowing the data packet through to the end of the system. In FIG. 1, the uncorrectable error occurs in a bus 1 between an existing node A and an existing node B (which is represented by Occurrence of UE in FIG. 1). In this case, the existing node B receiving the uncorrectable data from the existing node A detects the uncorrectable error (which is represented by Detection of UE in FIG. 1). Then, the existing node B executes a poisoning process about the ECC attached to the uncorrectable data, and transmits the data packet containing the poisoning data to an existing node C.
The existing node C can recognize the poisoning data attached to the uncorrectable data and therefore, even when receiving the data packet containing the poisoning data, detects none of the uncorrectable error. Then, the existing node transmits the data packet containing the poisoning data to an existing node D. Thus, the detection of the uncorrectable error is made by only the existing node B but gets unnecessary in the existing node C and in the existing node D, thereby improving the fault detection rate.
There has hitherto been a poisoning data recognizing method in a case based on such a premise of the system that all of the nodes are capable of recognizing the poisoning data attached to the uncorrectable data.
[Patent document 1] Japanese Patent Application Laid-Open Publication No. 2004-242294